dom-traversal

问题 I have a question. Let's say we have the following html tag: <div id='foo'>I am a div</div> Τhis div exists on the dom(it is not generated by javascript) If I want to use this div in javascript many times which is the better way to do it? store it in a variable like this: var d = $("#foo") or call it every time with jquery?: $("#foo").methodName() Which method does involve less dom traversal? 回答1: The fastest way is: document.getElementById("foo"); Setting this to a variable for reuse will

问题 I am trying to learn jQuery, I have following mark up In a div, I have two texts date and description and two buttons edit and delete. When I click the edit button, I want to get the date and description of that div Here I am trying to get it using parents() selector, how can I use closest() selector here , if it is not possible with the current markup please suggest how can I proceed with closest() selector. $(document).ready(function() { //If i click on edit button . I want to select the

问题 I am trying to learn jQuery, I have following mark up In a div, I have two texts date and description and two buttons edit and delete. When I click the edit button, I want to get the date and description of that div Here I am trying to get it using parents() selector, how can I use closest() selector here , if it is not possible with the current markup please suggest how can I proceed with closest() selector. $(document).ready(function() { //If i click on edit button . I want to select the

问题 Do getElementsByClassName (and similar functions like getElementsByTagName and querySelectorAll ) work the same as getElementById or do they return an array of elements? The reason I ask is because I am trying to change the style of all elements using getElementsByClassName . See below. //doesn't work document.getElementsByClassName('myElement').style.size = '100px'; //works document.getElementById('myIdElement').style.size = '100px'; 回答1: Your getElementById() code works since IDs have to be

问题 im trying to find out how to see if an error is returned from an AJAX request. for testing the request always returns <p id="error">test</p> I thought you could do it like this: //html is the var which contains the result var DOM = $(html); if( $('#error', DOM ).length != 0 ) { alert(html); } but this does not work. Can anyone shine a light on whats going wrong? 回答1: If your HTML isn't wrapped in something (like a div ) then it needs to be. var html = '<div></div><p id="error">ERROR!</p><span

问题 There are a lot of questions about whether or not finding an element is faster via class or id or some other selector. I'm not interested in that. I want to know if you have: var link = $(this); //let's say you're in a click handler Is it faster to find the container by doing var container = link.closest('.container'); //assume container is .container or var container = $('#mycontainer'); //assume same element as above I'm asking this question not just for the particular scenario above (ok,

问题 I'd like to take the code found here: http://www.jslab.dk/articles/non.recursive.preorder.traversal.part2 // HTML element var root = document.documentElement; recursivePreorder(root); // Recusively find and handle all text nodes function recursivePreorder(node) { // If node is a text node if (node.type == 3) { // Do something with node } // else recurse for each child node else { for(var i=0; i<node.childNodes.length; i++) recursivePreorder(node.childNodes[i]); } } and convert it into clean

问题 I am trying to find a <td> where the value is 5. It is a calender so there will only be one 5 value. 回答1: You can use filter method: $('td').filter(function(){ return $(this).text() === '5' }) 回答2: Use the :contains selector: var td = $("td:contains('5')"); Edit: This will also select the td with 15 and 25 , if you want exact 5 , then use the .filter method as the other answer said. 来源： https://stackoverflow.com/questions/12746846/jquery-find-table-cell-where-value-is-x

问题 I'm in the middle of an .each iteration and wanted to call out the 2nd or 3rd child for the each..but cant make it work. alert($(this + ' :nth-child(2)').attr('id')); My only option that I can think of is something terrible goofy like this: $(this).children(':first').next().attr('id', 'ddParam' + newCount); $(this).children(':first').next().next().attr('id', 'txt' + newCount); $(this).children(':first').next().next().next().attr('id'... 回答1: What you need is context. With context, the

问题 I'm in the middle of an .each iteration and wanted to call out the 2nd or 3rd child for the each..but cant make it work. alert($(this + ' :nth-child(2)').attr('id')); My only option that I can think of is something terrible goofy like this: $(this).children(':first').next().attr('id', 'ddParam' + newCount); $(this).children(':first').next().next().attr('id', 'txt' + newCount); $(this).children(':first').next().next().next().attr('id'... 回答1: What you need is context. With context, the